Lonesome Lake

Lonesome Lake is an earth dam located in Malheur County, Oregon. It carries a High hazard potential classification and has a poor condition assessment.

About Lonesome Lake

The primary purpose of Lonesome Lake is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Heartwood Properties Llc (private).

The dam stands 35 feet tall, and has a storage capacity of 186 acre-feet.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 08/26/2020.

At 35 feet, this dam is taller than 82% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Oregon dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardPoor ConditionEmergency Action Plan: No

Location

StateOregon
CountyMalheur
Coordinates43.60772, -117.02691

Physical Characteristics

Dam TypeEarth
NID Height35 ft
Dam Height35 ft

Storage & Hydraulics

NID Storage186 acre-ft
Normal Storage186 acre-ft

Ownership & Safety

PurposeIrrigation
OwnerHeartwood Properties LLC
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentPoor
Last Inspection08/26/2020
Emergency Action PlanNo

Identifiers

NID IDOR03792
Federal IDOR03792
More InfoState Dam Safety Program

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